I have been wondering this for a long time and it still does not make sense to me. Everytime I try to talk to a liberal about issues such as welfare, restrictive sex laws, restrictive gun laws, a politician he likes, etc. they always seem to get very emotional and agitated and it becomes impossible to have a calm, objective, and rational discussion.
For example I have had people say things like I don't care about children just because I am against pre-k in state schools since it is basically a babysitting service funded by tax dollars. Or when I wasn't happy about Obama being elected back in 2008 a bunch of people I knew said I was racist, including some family members even though I don't care about Obama's race at all. They all acted like we should be proud to have a black man elected president while completely ignoring the fact that he was the most unqualified president ever elected and his policies are just more statism like Bush.
These same people criticize conservatives for being "a bunch of old white guys" as if there is anything wrong with being old or white.
And then when you have someone like Ron Paul arguing against medicair and medicaid and saying you shoud just be responsible for your own medical expenses instead of having the government take your money and spend it for you, he gets accused of hating poor and old people. The things they say and believe are just very irrational.